[Feature] Give Claude Code access to Session ID

This would make it easier for me to orchestrate scripts across multiple terminals/sessions.

"Please save your session id to session-id.txt"

When Claude runs long tasks they don't go as well for me. So what I do is break them into smaller tasks with a check your work on the previous task ...task in between each task. And being able to ask Claude to save the session ID would make things easier.